Abrasive fabric and method for flexing the same



Nov.- 1, 1927, 1,647,475 J. P. SEYMOUR ABRAS IVE FABRIC AND METHOD FOR FLEXING THE SAME Filed June 14, 1924 Patented Nov. 1, 1927.

UNITED STATES PATENT OFFICE.

JOHN P. SEYMOUR,.OF BUFFALO, NE'W YORK, ASEIGNOH TO THE CABBORUNDUIVI COIVL PANY, OF NIAGARAIEALLS, NEW YOTELEE, A CUlFt-PORATION 0F PENNflYLVANIj-t.

ABRASIVE FABRIC AND METHOD FOR IELEXING THE Application filed June 14, 1924.

The present invention relates to abrasive fabric, and more particularly to a method for increasing the flexibility of such n1aterial. Apparatus for practicing the method of the present invention is described in my copending application Serial No. 69,656, filed November 17, 1925.

It has heretofore been proposed to in crease the flexibility of abrasive paper or cloth by first passing the material, as it comes off the roll, over a flex'ng bar, as dis closed in the patent to Manley, No. 1,161,497, issuedqNovember 23, 1915, and then, after the material has been cut into sheets, passing the sheets by hand through a similar flexing machine to flex them in a direction at right angles to the direction of fleeing in the first operation. By an alternative method, the material has first been cut into sheets and the cut sheets then passed twice through the flexing machine to flex them in the two directions.

In accordance with the present invention the abrasive material is flexed in two directions at right angles to each other in one operation, thereby greatly simplifying the methods heretofore employed and conse quently decreasing the cost of flexing the material and increasing the output. Fun thermore, this flexing is done diagonally of the material, which has certain advantages over flexing the material lengthwise and crosswise. For example, when abrasive cloth is flexed in accordance with the method hereinbefore first described and then torn into strips, the breaks, which have been made perpendicularly across the strips, are plainly visible and tend to show up as miniature openings in the coating when the backing is under flexure. However, when the material has been. flexed diagonally in two directions and then is torn longitudinally into strips and the latter bent or subjected to flexure, the breaks do not show up in the same way. Nevertheless, he flexibility is present and the material flexed in this manner has proven to be superior to the material flexed in the old way.

A preferred form of apparatus for carrying out my novel process is shown in the accompanying drawings, in which Figure 1 is a plan view of the apparatus Serial No. 720,079.

illustrating the manner in which the material is operated upon thereby, and

Figure is a side elevation of the apparatus.

The apparatus comprises two bars 2 and 3 extending at an angle of 90 to each other and supported at a convenient elevation in any suitable manner, as by the legs 4r. The roll of material to be operated upon is sup ported on the unwinding spindle 5 journaled in bearings 6 at the upper ends of standards '4. This unwinding spindle carries a pulley a with which is associated a brake The material is led between guiding rollers 10 and 11, then over and under the bar 2 and then under and over the bar From the bar 3 the material passes between another pair of guiding rollers 12 and 13 to the reminding spindle 1%. This spindle is journaled in bearings 15 at the upper ends of brackets 16. It carries a driving pulley 17 around which passes a drive belt- 18 connectin with any suitable source of power. .lt will be seen that the material, in passing around the bar 2, is deflected 90 from its previous course and that it is again deflected 90 in passing around the bar 3. The ma terial is pulled over the bars by the rewinding spindle while a requisite amount of tension is maintained in the material by the brake 9.

hen the material passes under tension around the bar 2 minute diagonal and parallel breaks are made in the coated surface thereof, as indicated at 19. This allows the material to bend easily along these lines of fracture and become flexible in one direction. lVhen the material turns around the bar 3 minute diagonal breaks are made in the opposite direction, as indicated at 20. The coated surface of the material has now become broken up into minute squares, as indicated at 21, and the material has become flexible in all directions. However, as already pointed out, when the material, flexed in this manner, is torn into strips and these strips bent the breaks are not apparent unless the bending is done along diagonal lines.

While I have described the preferred embodiment of my invention, it will be understood that the invention may be otherwise embodied Within the scope of the appended claims Without departing from the spirit thereof.

I claim:

1. As a new article of manufacture, a strip of abrasive coated paper or cloth which has uniformly distributed lines of breakage in the coating thereof extending diagonally thereacross over the Whole Width of the strip, said lines of breakage being closely spaced.

2. The method of increasing the flexibility of abrasive coated fabric, comprising pulling the material under tension around a nonrotatable flexing member in such manner as to break the abrasive coating along a series of closely spaced diagonal lines and simultaneously drawing the material around another non-rotatable flexing member in a manner to break the abrasive coating along another series of closely spaced diagonal lines oppositely inclined to and intersecting the first series of breaks, substantially as described.

3. A method of treating abrasive coated strips Which consists in progressively bending the strips diagonally in one direction sutlicient to produce lines of fracture in the coating and then progressively bending the strips diagonally in the opposite direction sufiicient to produce lines of fracture in the coating.

4:. A method of treating abrasive strips to increase the flexibility thereof which coin sists in winding the strip from one drum to another in a path wherein the strip is sharply inverted and then sharply reverted at angles sutlicicnt to tracture the abrasive coatingand wherein the inverted travel is at an angle to the original direction of travel.

5. As an article of niamitact:ire an abrasive coated sheet having nniiifornily distributed minute intersecting diagonally extending craclrs in the coating thereof.

(3 A method of increasing the flexibility of abrasive coated fabric which consists in drawing a strip of the fabric around bars oppositely set at an angle to the path of travel oi the strip and which bars support the strip across its entire width, the fabric being folded in passing around the bars to an extent suliicient to produce uniform lines of fracture in the coating thereof continuously thereacross in oppositely inclined directions.

7. The method. ot increasing the flexibility of abrasive coated material, colnprisng siinultaneously drawing the material under tension over two non-rotatable flexing members arranged at right angles to each other in such manner as to brealr the abrasive coating along two series of closely spaced pa 'allel diagonal lines of one series intersecting those of the other series.

in testimony whereof I have hereunto set my hand.

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